Quantum mechanics

Magnetic field

Linguistics

Composite number

Philosophy

Materials science

Stress (linguistics)

Bioelectronics

Biosensor

Physics

Nanotechnology

Dipole

Composite material

Magnetostriction

Polydimethylsiloxane

Cantilever

Nature Materials

The magnetoelastic effect—the variation of the magnetic properties of a material under mechanical stress—is usually observed in rigid alloys, whose mechanical modulus is significantly different from that of human tissues, thus limiting their use in bioelectronics applications. Here, we observed a giant magnetoelastic effect in a soft system based on micromagnets dispersed in a silicone matrix, reaching a magnetomechanical coupling factor indicating up to four times more enhancement than in rigid counterparts. The results are interpreted using a wavy chain model, showing how mechanical stress changes the micromagnets’ spacing and dipole alignment, thus altering the magnetic field generated by the composite. Combined with liquid-metal coils patterned on polydimethylsiloxane working as a magnetic induction layer, the soft magnetoelastic composite is used for stretchable and water-resistant magnetoelastic generators adhering conformably to human skin. Such devices can be used as wearable or implantable power generators and biomedical sensors, opening alternative avenues for human-body-centred applications. Micromagnets dispersed in a polymer matrix are used to realize a soft magnetoelastic generator with high magnetomechanical coupling factor, used for wearable and implantable power generation and sensing applications.

Giant magnetoelastic effect in soft systems for bioelectronics